Accurate, real-time, and detailed knowledge of a population distribution is important for urban planning, advertising, navigation, and other activities. A census may give a static measurement (e.g. a snapshot) of the population at significant cost and with limited detail. However, population, especially in urban areas is not static. For example, people may live outside a city and commute into the city during the day. Residents of the city may leave the city on the weekends. The population in a city, state, or region may therefore change on an hourly or daily basis. This dynamic behavior of the population may not be captured by a static population measurement in a census.